Development of a wideband compact leaky wave cavity antenna

As operating frequencies decrease, the aperture size of leaky wave antennas increases significantly - rendering them unsuitable for many sophisticated applications requiring small-sized communication antennas. In this article, a compact leaky wave cavity antenna with wide impedance bandwidth, using tapered cavity with substrate integrated waveguide is proposed. The antenna consists of a substrate and a rectangular metallic cavity fed by an L-shaped feed element. The metallic strips are placed along the sides of the substrate to fabricate a substrate integrated waveguide. The cavity is tapered to steer the beam in the desired direction. The tapering of the cavity causes the placement of the L-shaped feed element near the back wall of the cavity, producing input impedance mismatching. This problem of input impedance mismatching is resolved by the substrate integrated waveguide. It is demonstrated that the proposed antenna is compact (2 lambda(0)), and is wideband with voltage standing wave ratio (VSWR) bandwidth of 24% for 2:1 VSWR and a gain of 8.4 dBi. The experimental results for the designed antenna are in close agreement with the simulation results. The proposed antenna can be utilized in different wireless applications such as mobile communications, road vehicle communications and other applications.